SiO2/Ag microbeads were synthesized using the electroless plating method by changing the addition order and the mixed method of electroless plating. Conducting composites were prepared using the ...prepared SiO2/Ag microbeads and unsaturated polyester resin as the fillers and substrate, respectively. The microstructure and properties of the prepared microbeads and composite were characterized with a scanning electron microscope (SEM), X-ray diffractometer (XRD), energy dispersive spectrometer (EDS), particle size analyzer, DC milliohm meter and vector network analysis tester. Results show that the SiO2/Ag microbeads prepared with the reverse dropping electroless plating method achieved the best uniformity and integrity of the silver coating on the surfaces of glass beads, and its compaction resistance reached 138.80 mΩ·cm. When the ratio of the prepared SiO2/Ag microbeads and unsaturated polyester resin was 1:2, the obtained coating composite had a resistivity of 2.79 × 10–5 Ω·cm, showing good electromagnetic shielding performance.
With the goals of protecting boiler tubes from hostile surroundings, increasing thermal efficiency, and minimizing time losses from damage, thermal-spray coating methods for high-temperature ...operations were created. Ceramic-metal composite materials (e.g., Cr3C2-NiCr) are well known for protecting components from erosion decay in a high-temperature environment. In this investigation, the high-velocity oxy-fuel (HVOF) thermal-spray technique was employed to successfully deposit several variations of feedstocks containing Cr3C2-NiCr and NiCr powders onto a medium-carbon steel substrate, with and without filtering through a 400-mesh screen. Utilizing X-ray fluorescence (XRF), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD), the microstructure features of the deposited coatings were assessed. The experiment results demonstrate that the crystallite and grain sizes of the deposited coatings can be increased by reducing the powder size through a sifting process using a 400-mesh sieve. This procedure also resulted in a coating with a higher density and lower porosity. Furthermore, new compounds including Cr2O3 and MnCr2O4 were formed in the coating layers as indicated by the XRD spectra. These phenomena are in good agreement with the EDS mapping of Cr and O, which reveals highly similar distributions. Manganese was originally a part of the substrate composition. Manganese could diffuse rapidly across the Cr2O3 layer and form the MnCr2O4 compound, indicating the manganese diffusion from the substrate into the Cr3C2-NiCr coating. The formation of MnCr2O4 can be attributed to the prior emergence of the Cr2O3 compound.
Predmet je prispevala v akciji Zbiramo spomine 2022, Stari običaji in predmeti, ki so se nekoč uporabljali in ga hrani Kapelj Damjana.Na fotografiji je ročno izvezena prevleka za blazino. Prevleko je ...»naštikala« Marija Kapelj okoli leta 1970. Ženske so si zaradi pomankanja denarja kupile blago in si same šivale rjuhe in blazine, ter na njih izvezle različne vzorce. S tem so si krajšale dolge zimske večere.
